wagon has 17 distinct synonyms spread across 5 of its 5 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
any of various kinds of wheeled vehicles drawn by an animal or a tractor
van used by police to transport prisoners
a group of seven bright stars in the constellation Ursa Major
a child's four-wheeled toy cart sometimes used for coasting
a car that has a long body and rear door with space behind rear seat
Synonyms, antonyms and the broader and narrower relations for wagon come from Princeton University’s WordNet. Full sources and licences.